Removing/Adding 在 ConstraintLayout 中以编程方式约束

Question

我想根据某些条件以编程方式删除和添加约束。以下是屏幕截图：

我想像这样删除它，但在代码中：

所以想以编程方式实现同样的效果

这是我试过的代码：

    if (advertisements.size() > 0) { //my own condition
        ConstraintLayout.LayoutParams layoutParams = (ConstraintLayout.LayoutParams) btnCreateAd.getLayoutParams();
        layoutParams.topToBottom = R.id.imvEmpty; //the imageview that is in center of the view
        btnCreateAd.setLayoutParams(layoutParams);
        recyclerView.setVisibility(View.VISIBLE);
        txvMyAdEmptyText.setVisibility(View.GONE);
        imvEmpty.setVisibility(View.GONE);
        adapter.setList(advertisements);
        adapter.notifyDataSetChanged();
    } else {
        ConstraintLayout.LayoutParams layoutParams = (ConstraintLayout.LayoutParams) btnCreateAd.getLayoutParams();
        layoutParams.topToBottom = -1; //here i am trying to remove top constraint but it doesn't work
        btnCreateAd.setLayoutParams(layoutParams);

        recyclerView.setVisibility(View.GONE);
        txvMyAdEmptyText.setVisibility(View.VISIBLE);
        imvEmpty.setVisibility(View.VISIBLE);
        adapter.setList(new ArrayList<Advertisement>());
    }
    mConstraintView.invalidate(); //this is my constraint view

编辑

我也有 tried using ConstraintSet，但结果甚至有所不同，我的 RecyclerView（设置为父视图的边界）正在消失

 ConstraintSet set = new ConstraintSet();
    set.clone(parentView);

    if (advertisements.size() > 0) {

        recyclerView.setVisibility(View.VISIBLE);
        txvMyAdEmptyText.setVisibility(View.GONE);
        imvEmpty.setVisibility(View.GONE);
        adapter.setList(advertisements);
        adapter.notifyDataSetChanged();

    } else {

        set.connect(btnCreateAd.getId(), ConstraintSet.TOP, imvEmpty.getId(), ConstraintSet.BOTTOM, 0);

        recyclerView.setVisibility(View.GONE);
        txvMyAdEmptyText.setVisibility(View.VISIBLE);
        imvEmpty.setVisibility(View.VISIBLE);
        adapter.setList(new ArrayList<Advertisement>());
    }
    set.connect(btnCreateAd.getId(), ConstraintSet.END, ConstraintSet.PARENT_ID, ConstraintSet.END, 0);
    set.connect(btnCreateAd.getId(), ConstraintSet.START, ConstraintSet.PARENT_ID, ConstraintSet.START, 0);
    set.connect(btnCreateAd.getId(), ConstraintSet.BOTTOM, ConstraintSet.PARENT_ID, ConstraintSet.BOTTOM, 0);

    set.applyTo(parentView);

Answer 1

我没有完成你的代码，但下面说明了如何使用 ConstraintSet.

打破和建立约束

ConstraintSet set = new ConstraintSet();
ConstraintLayout layout;

layout = (ConstraintLayout) findViewById(R.id.layout);
set.clone(layout);
// The following breaks the connection.
set.clear(R.id.bottomText, ConstraintSet.TOP);
// Comment out line above and uncomment line below to make the connection.
// set.connect(R.id.bottomText, ConstraintSet.TOP, R.id.imageView, ConstraintSet.BOTTOM, 0);
set.applyTo(layout);

Answer 2

另一种方法是使用 ConstraintLayout.LayoutParams.UNSET。这种方式不使用 ConstraintSet.clear.

假设我们要删除 constraintLayout 本身的底部约束，但可以是任何视图：

val containerParams = cl_container.layoutParams as ConstraintLayout.LayoutParams
containerParams.bottomToBottom = ConstraintLayout.LayoutParams.UNSET
cl_container.layoutParams = containerParams

Answer 3

这是来自 j2emanue using ConstraintLayout.LayoutParams 的答案的 Java 版本，它在不指定布局所限制的元素的 ID 的情况下工作：

final ConstraintLayout constraintLayout = findViewById(R.id.constraintLayout);
final ConstraintLayout.LayoutParams layoutParams = (ConstraintLayout.LayoutParams) constraintLayout.getLayoutParams();
layoutParams.bottomToBottom = ConstraintLayout.LayoutParams.UNSET;
constraintLayout.setLayoutParams(layoutParams);

Answer 4

如果您将 viewBinding/dataBinding 与 Kotlin 一起使用，现在有一种更简单的方法。

有一个名为 updateLayoutParams 的扩展函数来自 import androidx.core.view.updateLayoutParams 并像下面那样使用它


    binding.yourView.updateLayoutParams<ConstraintLayout.LayoutParams> {
                        this.startToEnd = ConstraintLayout.LayoutParams.UNSET
                      this.startToStart = ConstraintLayout.LayoutParams.PARENT_ID
                    }

Removing/Adding 在 ConstraintLayout 中以编程方式约束

Removing/Adding constraint programmatically in ConstraintLayout

android

android-layout

android-constraintlayout

android-layoutparams